Radiation image processing device, radiation image processing method, and radiation image processing program

A radiation image processing method comprising:

• via a computer,
• acquiring a first radiation image and a second radiation image which are acquired by imaging a subject, which includes a first component consisting of a plurality of compositions and a second component consisting of a single composition, with radiation having different energy distributions;
• deriving an initial second component image in which the second component is emphasized, based on the first radiation image and the second radiation image;
• specifying a second component region including the second component in the first radiation image or the second radiation image based on the initial second component image;
• specifying a region other than the second component region in the first radiation image or the second radiation image as a first component region including only the first component;
• deriving a characteristic of the first component related to attenuation of the radiation based on the first radiation image and the second radiation image in the specified first component region in the first radiation image or the second radiation image;
• deriving the characteristic of the first component in the specified second component region in the first radiation image or the second radiation image based on the characteristic of the first component derived in the first component region around the second component region;
• and
• deriving a first component image in which the first component is emphasized and a second component image in which the second component is emphasized, based on the characteristic of the first component derived in each of the first component region and the second component region in at least a region of the subject in the first radiation image or the second radiation image.

A non-transitory computer-readable storage medium that stores a radiation image processing program causing a computer to execute:

• a procedure of acquiring a first radiation image and a second radiation image which are acquired by imaging a subject, which includes a first component consisting of a plurality of compositions and a second component consisting of a single composition, with radiation having different energy distributions;
• a procedure of deriving an initial second component image in which the second component is emphasized, based on the first radiation image and the second radiation image;
• a procedure of specifying a second component region including the second component in the first radiation image or the second radiation image based on the initial second component image;
• a procedure of specifying a region other than the second component region in the first radiation image or the second radiation image as a first component region including only the first component;
• a procedure of deriving a characteristic of the first component related to attenuation of the radiation based on the first radiation image and the second radiation image in the specified first component region in the first radiation image or the second radiation image;
• a procedure of deriving the characteristic of the first component in the specified second component region in the first radiation image or the second radiation image based on the characteristic of the first component derived in the first component region around the second component region;
• and
• a procedure of deriving a first component image in which the first component is emphasized and a second component image in which the second component is emphasized, based on the characteristic of the first component derived in each of the first component region and the second component region in at least a region of the subject in the first radiation image or the second radiation image.